In a microwave communication system (Microwave Communication System), signals are generally transmitted by applying a multi input multi output (Multi input Multi output, MIMO) technology to improve a utilization ratio of a channel spectrum, thereby achieving the purpose of expanding transmission capacity. In actual application, in general, a channel of the microwave communication system is a line of sight (Line of Sight, LOS) channel, a channel matrix is not completely orthogonal in this environment, and the number of channel conditions is seriously sick, and therefore, it is difficult to support a relatively independent data stream. Moreover, phase noise of the microwave communication system is more serious than that of a wireless communication system, and how to effectively suppress the phase noise so as to improve the performance of the whole microwave communication system is always a research hotspot in this field.
The existing phase noise suppression architecture is usually applied to a receiver of the microwave communication system. In general, the existing phase noise suppression architecture is formed by a space-time equalizer, a phase-locked loop, and a combiner, and its working process is summarized as follows: the space-time equalizer receives each input signal, performs equalization processing on the each input signal, and outputs an equalized signal to the phase-locked loop; the phase-locked loop suppresses the phase noise of the each signal output by the space-time equalizer; and multiple channels of signals output by the phase-locked loop are superposed by the combiner to obtain a received signal.
In the foregoing phase noise suppression architecture, the phase noise suppression depends on the bandwidth of the phase-locked loop. The phase-locked loop is caused to be divergent if the bandwidth of the phase-locked loop is set to be too large. Therefore, the bandwidth of the phase-locked loop is set to be relatively narrow under the normal circumstance, thereby limiting suppression capability on the phase noise.